Abstract:
Disclosed are a wavelength-division multiplexing optical communication system and a method for measuring optical performance of an output signal for the system. The optical communication system according to one embodiment comprises: a service-provider device; a local node; and a plurality of subscriber devices. The service-provider device comprises: a plurality of first optical transceivers; a first optical multiplexer/demultiplexer (OD/OM) connected to the plurality of first optical transceivers so as to multiplex/demultiplex the light transceived by the plurality of first optical transceivers; and a seed-light source providing seed light. Each of the plurality of subscriber devices comprises a second optical transceiver. The local node connects the service-provider device and the plurality of subscriber devices to each other using a DWDM link comprising: a second multiplexer/demultiplexer (OD/OM); and a single-mode optical fiber for transmission. Here, the optical intensity of an output signal of the second optical transceiver is determined by compensating for the value of the loss caused when the output signal passes through the second optical multiplexer/demultiplexer of the local node.
Abstract:
The present invention relates to an IPTV service device and method for providing continuous service. The method according to one embodiment of the present invention comprises: a service-request receiving step of receiving an IPTV service request from a user of an IPTV terminal; a service-confirming step of confirming whether or not the IPTV service has previously been stopped in response to the IPTV service request; and an IPTV-service providing step of providing the IPTV service to the IPTV terminal from the point at which service was stopped if the IPTV service has previously been stopped.
Abstract:
Disclosed is a technique in which multiple antennas are applied to a mobile communication system using a single carrier frequency division multiple access method. A transmission apparatus includes a layer mapper to map a modulated symbol to a plurality of layers, a layer shifter to uniformly divide the symbol mapped to each of the plurality of layers, in a plurality of time domain streams, and a signal transmission unit to perform a DFT on each of the plurality of time domain streams to generate a plurality of frequency domain streams, and to transmit, to a receiving apparatus, the plurality of frequency domain streams using a plurality of antennas corresponding to each of the plurality of frequency domain streams.
Abstract:
The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.
Abstract:
A method and apparatus of encoding and decoding an Extensible Markup Language (XML) document using a path code is provided. A method of encoding an XML document, the method including: searching the XML document for all element tags and all attributes including character data; extracting an XPath of each of the retrieved element tags and attributes; converting the extracted XPath into a predetermined path code; and expressing an occurrence indicator of each of all element tags included in the converted XPath.
Abstract:
Disclosed are a method for determining a color difference component quantization parameter and a device using the method. Method for decoding an image can comprise the steps of: decoding a color difference component quantization parameter offset on the basis of size information of a transform unit; and calculating a color difference component quantization parameter index on the basis of the decoded color difference component quantization parameter offset. Therefore, the present invention enables effective quantization by applying different color difference component quantization parameters according to the size of the transform unit when executing the quantization.
Abstract:
Disclosed is an entropy coding method using an index mapping table, and an apparatus using the method. An image-decoding method comprises: a step of mapping an inputted codeword to a code number with reference to an inverse codeword mapping table, and calculating the mapped code number in a table index; and a step of updating the inverse mapping table based on the accumulated number of occurrences of the code number, the number of sequential occurrences of the code number, neighbor block encoding/decoding information, and/or threshold value information for updating the inverse index mapping table. According to the present invention, an index mapping table is realigned based on a certain condition, thereby improving encoding/decoding efficiency.
Abstract:
The invention relates to a video communication device, comprising a first camera and a second camera which are arranged at different locations so as to form a symmetrical relationship about a reference point in the periphery of a video display screen. The video communication device performs video communication based on images acquired from the first camera and second camera, respectively, and also changes a communication mode in response to a request for a change of communication mode.
Abstract:
Disclosed are a method for checking whether D2D communication between devices for performing D2D communication is possible, and a method for estimating the proximity of devices to base stations and the proximity of devices to one another for reusing wireless resources in device-to-device communication and terminal relay communication. The method according to the present invention may enable the verification of whether D2D communication is possible between devices to establish a D2D connection, and may enable the wireless resources allocated to a cellular link and to other D2D links to be reused. Further, the method of the present invention may enable variations in a link state caused by terminal mobility to be handled, as well as D2D communication between new UEs and D2D communication between a new UE and a legacy UE, to be handled.
Abstract:
An inter prediction method according to the present invention comprises: a step for deriving reference motion information related to a unit to be decoded in a current picture; and a step for performing motion compensation for the unit to be decoded, using the reference motion information that has been derived. According to the present invention, image encoding/decoding efficiency can be enhanced.